In broad strokes, figuring what a dinosaur ate is simple. Carnivores, herbivores, and omnivores are separated from each other on the basis of their teeth and other anatomical clues. But in trying to envision what these unusual animals were like in life - and understand their ecology - these traditional categories are far too broad and hardly satisfying. When we ask "What did this dinosaur eat?", "Plants" isn't much of an answer. Fortunately for us, sometimes dinosaur skeletons come with remnants of their last meals.

Isaberrysaura is a relatively new dinosaur on the block, named by paleontologist Leonardo Salgado and colleagues earlier this year. This 170 million year old creature was one of the ornithischians, close to the base of a dinosaur family that would come to include rock stars like Iguanodon and Edmontosaurus. But the most remarkable thing about this dinosaur, the researchers reported, was what was found inside its body cavity.

From the teeth alone, Isaberrysaura looked a good candidate for an herbivore. Its small, leaf-shaped teeth were better suited to cropping vegetation and cutting flesh. But the real confirmation of its diet comes from cycad seeds fossilized within the dinosaur's gut.

The preservation of the seeds indicate that they were "gobbled down, and not chewed", Salgado and coauthors wrote. That makes sense given that dinosaurs like Isaberrysaura could not chew. But beyong mere association, this raises the prospect of ecological ties we would have otherwise been blind to. The sturdy cycad seeds likely passed through living Isaberrysaura digestive systems intact, deposited in various places as the dinosaur roamed. Isaberrysaura may have been a seed disperser, planting the Jurassic garden.

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